WARNINGS
Clinical Worsening And Suicide Risk
Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of
their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes
in behavior, whether or not they are taking antidepressant medications, and this risk may persist until
significant remission occurs. Suicide is a known risk of depression and certain other psychiatric
disorders, and these disorders themselves are the strongest predictors of suicide. There has been a
long-standing concern, however, that antidepressants may have a role in inducing worsening of
depression and the emergence of suicidality in certain patients during the early phases of treatment.
Pooled analyses of short-term placebo-controlled trials of antidepressant drugs (SSRIs and others)
showed that these drugs increase the risk of suicidal thinking and behavior (suicidality) in children,
adolescents, and young adults (ages 18 to 24) with major depressive disorder (MDD) and other
psychiatric disorders. Short-term studies did not show an increase in the risk of suicidality with
antidepressants compared to placebo in adults beyond age 24; there was a reduction with antidepressants
compared to placebo in adults aged 65 and older.
The pooled analyses of placebo-controlled trials in children and adolescents with MDD, obsessive
compulsive disorder (OCD), or other psychiatric disorders included a total of 24 short-term trials of 9
antidepressant drugs in over 4400 patients. The pooled analyses of placebo-controlled trials in adults
with MDD or other psychiatric disorders included a total of 295 short-term trials (median duration of 2
months) of 11 antidepressant drugs in over 77,000 patients. There was considerable variation in risk of
suicidality among drugs, but a tendency toward an increase in the younger patients for almost all drugs
studied. There were differences in absolute risk of suicidality across the different indications, with the
highest incidence in MDD. The risk differences (drug vs. placebo), however, were relatively stable
within age strata and across indications. These risk differences (drug-placebo difference in the number
of cases of suicidality per 1000 patients treated) are provided in Table 1.
Table 1
Age Range |
Drug-Placebo Difference in
Number of Cases of Suicidality
per 1000 Patients Treated |
Increases Compared to Placebo |
<18 |
14 additional cases |
18-24 |
5 additional cases |
Decreases Compared to Placebo |
25-64 |
1 fewer case |
≥65 |
6 fewer cases |
No suicides occurred in any of the pediatric trials. There were suicides in the adult trials, but the
number was not sufficient to reach any conclusion about drug effect on suicide.
It is unknown whether the suicidality risk extends to longer-term use, i.e., beyond several months.
However, there is substantial evidence from placebo-controlled maintenance trials in adults with
depression that the use of antidepressants can delay the recurrence of depression.
All patients being treated with antidepressants for any indication should be monitored
appropriately and observed closely for clinical worsening, suicidality, and unusual changes in
behavior, especially during the initial few months of a course of drug therapy, or at times of dose
changes, either increases or decreases.
The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility,
aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been
reported in adult and pediatric patients being treated with antidepressants for major depressive disorder
as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the
emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal
impulses has not been established, there is concern that such symptoms may represent precursors to
emerging suicidality.
Consideration should be given to changing the therapeutic regimen, including possibly discontinuing
the medication, in patients whose depression is persistently worse, or who are experiencing emergent
suicidality or symptoms that might be precursors to worsening depression or suicidality, especially if
these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms.
Families and caregivers of patients being treated with antidepressants for major depressive
disorder or other indications, both psychiatric and nonpsychiatric, should be alerted about the
need to monitor patients for the emergence of agitation, irritability, unusual changes in behavior,
and the other symptoms described above, as well as the emergence of suicidality, and to report
such symptoms immediately to health care providers. Such monitoring should include daily
observation by families and caregivers. Prescriptions for nortriptyline hydrochloride should be
written for the smallest quantity of capsules consistent with good patient management, in order to reduce
the risk of overdose.
Screening Patients For Bipolar Disorder
A major depressive episode may be the initial presentation
of bipolar disorder. It is generally believed (though not established in controlled trials) that treating
such an episode with an antidepressant alone may increase the likelihood of precipitation of a
mixed/manic episode in patients at risk for bipolar disorder. Whether any of the symptoms described
above represent such a conversion is unknown. However, prior to initiating treatment with an
antidepressant, patients with depressive symptoms should be adequately screened to determine if they
are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a
family history of suicide, bipolar disorder, and depression. It should be noted that nortriptyline
hydrochloride is not approved for use in treating bipolar depression.
Patients with cardiovascular disease should be given Pamelor only under close supervision because of
the tendency of the drug to produce sinus tachycardia and to prolong the conduction time. Myocardial
infarction, arrhythmia, and strokes have occurred. The antihypertensive action of guanethidine and
similar agents may be blocked. Because of its anticholinergic activity, Pamelor should be used with
great caution in patients who have a history of urinary retention. Patients with a history of seizures
should be followed closely when Pamelor is administered, inasmuch as this drug is known to lower the
convulsive threshold. Great care is required if Pamelor is given to hyperthyroid patients or to those
receiving thyroid medication, since cardiac arrhythmias may develop.
Pamelor may impair the mental and/or physical abilities required for the performance of hazardous
tasks, such as operating machinery or driving a car; therefore, the patient should be warned accordingly.
Excessive consumption of alcohol in combination with nortriptyline therapy may have a potentiating
effect, which may lead to the danger of increased suicidal attempts or overdosage, especially in patients
with histories of emotional disturbances or suicidal ideation.
The concomitant administration of quinidine and nortriptyline may result in a significantly longer plasma
half-life, higher AUC, and lower clearance of nortriptyline.
Serotonin Syndrome
The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and
SSRIs, including Pamelor, alone but particularly with concomitant use of other serotonergic drugs
(including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, and St.
John’s Wort) and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those
intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene
blue).
Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations,
delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness,
diaphoresis, flushing, hyperthermia), neuromuscular changes (e.g., tremor, rigidity, myoclonus,
hyperreflexia, incoordination), seizures, and/or gastrointestinal symptoms (e.g., nausea, vomiting,
diarrhea). Patients should be monitored for the emergence of serotonin syndrome.
The concomitant use of Pamelor with MAOIs intended to treat psychiatric disorders is contraindicated.
Pamelor should also not be started in a patient who is being treated with MAOIs such as linezolid or
intravenous methylene blue. All reports with methylene blue that provided information on the route of
administration involved intravenous administration in the dose range of 1 mg/kg to 8 mg/kg. No reports
involved the administration of methylene blue by other routes (such as oral tablets or local tissue
injection) or at lower doses. There may be circumstances when it is necessary to initiate treatment with
an MAOI such as linezolid or intravenous methylene blue in a patient taking Pamelor. Pamelor should be
discontinued before initiating treatment with the MAOI (See CONTRAINDICATIONS and DOSAGE AND ADMINISTRATION).
If concomitant use of Pamelor with other serotonergic drugs, including triptans, tricyclic
antidepressants, fentanyl, lithium, tramadol, buspirone, tryptophan, and St. John’s Wort is clinically
warranted, patients should be made aware of a potential increased risk for serotonin syndrome,
particularly during treatment initiation and dose increases.
Treatment with Pamelor and any concomitant serotonergic agents should be discontinued immediately if
the above events occur and supportive symptomatic treatment should be initiated.
Unmasking Of Brugada Syndrome
There have been postmarketing reports of a possible association between treatment with Pamelor and
the unmasking of Brugada syndrome. Brugada syndrome is a disorder characterized by syncope,
abnormal electrocardiographic (ECG) findings, and a risk of sudden death. Pamelor should generally be
avoided in patients with Brugada syndrome or those suspected of having Brugada syndrome.
Angle-Closure Glaucoma
The pupillary dilation that occurs following use of many antidepressant drugs including Pamelor may
trigger an angle-closure attack in a patient with anatomically narrow angles who does not have a patent
iridectomy.
Use In Pregnancy
Safe use of Pamelor during pregnancy and lactation has not been established; therefore, when the drug
is administered to pregnant patients, nursing mothers, or women of childbearing potential, the potential
benefits must be weighed against the possible hazards. Animal reproduction studies have yielded
inconclusive results.